Where to find Corsola in Sun, Moon, Ultra Sun & Ultra Moon

Super Rod: Route 9 (15%), Melemele Sea (5%), Hau'oli City (5%, Only in Ultra Sun & Ultra Moon)
SOS Encounter: Route 9, Melemele Sea
Surf: Hau'oli City (35%, Only in Ultra Sun & Ultra Moon), Melemele Sea (25%)
+ 1 more way

Corsola also appears in

How to get Corsola in Sun, Moon, Ultra Sun & Ultra Moon

Its base catch rate is 60 out of 255 (higher is easier); the catch rate calculator works out your odds with each ball. For the look, the best colour match is Love Ball or Heal Ball.

Corsola in every game · Pokémon Sun, Moon, Ultra Sun & Ultra Moon interactive map (Alola)